


Tsukishima Kryptonite©

by chromyrose



Series: SASO 2017 [3]
Category: Haikyuu!!
Genre: Alternate Universe - Canon Divergence, Children's Day, F/M, Family Fluff, Parenthood, Teen Pregnancy, Uncle-Nephew Relationship, Unplanned Pregnancy
Language: English
Status: Completed
Published: 2017-06-16
Updated: 2017-06-16
Packaged: 2018-11-14 16:17:40
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 970
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11211678
Author URL: https://archiveofourown.org/users/chromyrose/pseuds/chromyrose
Summary: Kei never asked to be an uncle, but he can't help the soft spot he has for his nephew.





	Tsukishima Kryptonite©

**Author's Note:**

> The prompt here was "in high school Akiteru accidentally knocked up Saeko and now Tsukishima has a blended family with Tanaka as his brother-in-law and the hardest life IN THE UNIVERSE"

Tsukishima Kei had outgrown Children's Day nearly a decade prior; apparently, his brother Akiteru had never gotten the message. 

“But you have to join us, Kei!” He repeated into the phone for the eighth time, practically whining. “Hayato is so excited to see you again, and Saeko is making us all a picnic. If you don't come, you'll make my son cry!” 

“Don't you mean you'll be the one who ends up crying,” Kei muttered into his phone, tapping his pencil against the desk irritably. He sighed a touch dramatically, just to drive his point home. “I can't come, I have a very important test the next day.”

“You're already at the top of your class,” Akiteru argued. “You can afford to take one day off of studying for one test, Kei.” 

“Oh? Are you encouraging me to skive off? Someone in this family has to go to college, and it wasn't you.” 

For a moment, there was silence from the other end of the line, and Kei wondered if he hadn't gone too far. Then his brother's voice returned, as bright as ever. 

“I'm giving Hayato the phone now, he wants to talk to you!” 

“Wait, _onii-san_ , don't–!” 

“Hello?” Inquired a little voice, bright and high-pitched in Kei's ear. He sighed. 

“Hello, Hayato. How are you today?” 

“I'm so happy! _Tou-san_ says you're coming with us to Children's day so we can play in the park together.” 

“Yeah, Hayato, about that–“

“– And _Kaa-san_ is making mochi and she let me hit it some times! And I gotta new kite and Ryuu- _oji_ is gonna show me volleyball!” 

Kei winced; another reason he didn't want to go. He saw enough of his senpai during the week, without having to spend his only day off with him. “That sounds like fun, Hayato, but Kei- _oji_ can't come.” 

“You... can't?” 

It should have been impossible to relay heartbreak over a phone line, but his nephew's voice was so small it actually hurt Kei's heart. Nothing should have been that powerful, but then his brother had to go and create some certified Tsukishima Kryptonite©.

Kei cleared his throat and continued before Hayato could start crying. “No, that's not what I meant. I can come. I just can't stay too long, okay?” 

Hayato sniffled. “But you promise you'll come, right? And play with me?” 

“Yeah. I. Promise.”

– 

Of course Akiteru and Saeko weren't the only parents who had decided to celebrate Children's Day with a picnic in the park, so by the time Kei got there the lawn was full of families with their screaming, squalling kids. He stepped over a few baby carriers and an alarming amount of spilled food, and was ultimately embarrassed by how easy it was to find his family; his sister in law had brought her _wadaiko_ drum, and was wearing her _happi_ coat and hand-decorated bandana. 

“Yo,” he said shortly as he approached their blanket, at which point a small honey-blond growth affixed itself to his leg. “Hayato-kun...” 

“You came!” Hayato squealed, rubbing his cheek into Kei's thigh affectionately. In the face of such cuteness even Kei couldn't help but lean over to pull his nephew into a proper hug, and sit Hayato in his lap when he finally sat down. 

“I told you I was going to come, remember? I promised.” 

“You did,” Hayato nodded. He hugged Kei again, and Akiteru laughed. 

“So good to see you, little bro. I guess that test wasn't so important after all?” 

“If I fail out of school, I'm making you explain it to mom.” 

Saeko laughed this time, and elbowed Akiteru playfully in the stomach. “I'm pretty sure that won't be the worst conversation we've had with your mom. We can handle it.”

Akiteru laughed again, and Kei looked away with a grimace before he got to witness his brother being cute with his wife; he'd seen enough of that at their wedding to last a lifetime. 

“Wanna see the kite _Tou-san_ got me?” Hayato asked, and without waiting for a response he scurried over to a pile of things and pulled a toy still wrapped in it's plastic out of the bottom. It was bright green, and Kei recognized it immediately.

“Is that a...?” 

“Dinosaur,” Akiteru confirmed, grinning. “It must run in the family.” 

“Speaking of things that run in the family...” Saeko started meaningfully, tilting her head towards the park entrance; Tanaka was there, wearing a headband that matched his sister's and holding a volleyball over his head. 

“Ryuu- _oji_!” Hayato screeched, holding up the kite. He stepped on Kei's calves as he got up and ran in the direction of his uncle, who scooped him up and let him sit on his shoulders. 

“Ryuu, you'd better not drop him!” Saeko warned, and Kei was certain he knew what side of his family Hayato got his powerful lungs from. 

“I won't, I know.” 

“Kei- _oji_ ,” Hayato whined, a little arm wrapped around Tanaka's head for stability. “I'm taller than you now!” He stuck his tongue out, which made Kei roll his eyes but get to his feet nonetheless.

“Barely. I am still taller than Tanaka.” 

Hayato's brow furrowed at this news, and he looked down at his legs dangling over Tanaka's shoulders, comparing that to Kei's. Immediately, he thrust his arms out in Kei's direction. 

“You carry me.” 

Tanaka made a dramatic, anguished noise as he knelt so that Hayato could switch to Kei's shoulders. Then he made a literal anguished noise when Hayato accidentally kicked him in the head. 

“Sorry,” Hayato said, not sounding sorry at all. He settled in around Kei and preened. “I can see the whole _world_ from here!” 

In spite of himself, Kei couldn't help but smirk. It may not have been his ideal Sunday, but he was glad he'd come after all.

**Author's Note:**

> If you enjoyed this, hit me up on [twitter](http://twitter.com/haikyuutiie) and come be my friend!


End file.
